Miriam Katherine McDonald (born July 26, 1987) is a Canadian actress best known for playing the lead role Emma Nelson on the Canadian television series Degrassi: The Next Generation.

McDonald was born in Oakville, Ontario to Silvia (née Pauksens), who is of Latvian descent, and John McDonald. She had an older sister Esther, who died from an eating disorder in 2013.

McDonald focused on acting, playing a role in the series, System Crash, in 1999. McDonald found a job as a voiceover actress after she was cast in 2001 in John Kricfalusi's series The Ripping Friends. She has done a total of 39 characters.

In 2001, she was cast as Emma Nelson, daughter of Christine 'Spike' Nelson, in the CTV/The N drama Degrassi: The Next Generation, a spin-off of the successful Degrassi series. She starred in the first nine series and three Degrassi television films. In 2016, she reprised the role for an episode in Degrassi: Next Class. She was also cast as Emma Jackson in the successful CTV show, Agent Wars, alongside Christopher J. Alexander, who played the main character, Christian.

In 2004, she played Dawn Gensler in the Lifetime made-for-television movie She's Too Young. She also had a guest role on the Family Channel show Naturally, Sadie as Heidi.

In 2008, she played Danielle "Daisy" Brooks in the made-for-TV erotic-thriller movie, Poison Ivy: The Secret Society.

In 2013, she played two roles in Lost Girl and also made an appearance in Orphan Black.

In 2018, McDonald appeared in Drake's music video for "I'm Upset", which took place during a Degrassi reunion.